0000000000740755
AUTHOR
R. J. H. Wesselink
Direct method for calculating temperature-dependent transport properties
We show how temperature-induced disorder can be combined in a direct way with first-principles scattering theory to study diffusive transport in real materials. Excellent (good) agreement with experiment is found for the resistivity of Cu, Pd, Pt (and Fe) when lattice (and spin) disorder are calculated from first principles. For Fe, the agreement with experiment is limited by how well the magnetization (of itinerant ferromagnets) can be calculated as a function of temperature. By introducing a simple Debye-like model of spin disorder parameterized to reproduce the experimental magnetization, the temperature dependence of the average resistivity, the anisotropic magnetoresistance and the spi…
Interface enhancement of Gilbert damping from first-principles
The enhancement of Gilbert damping observed for Ni_{80}Fe_{20} (Py) films in contact with the nonmagnetic metals Cu, Pd, Ta, and Pt is quantitatively reproduced using first-principles scattering calculations. The "spin-pumping" theory that qualitatively explains its dependence on the Py thickness is generalized to include a number of extra factors known to be important for spin transport through interfaces. Determining the parameters in this theory from first principles shows that interface spin flipping makes an essential contribution to the damping enhancement. Without it, a much shorter spin-flip diffusion length for Pt would be needed than the value we calculate independently.